11 documents found in 205ms
# 1
Roessler, Dirk • Passarelli, Luigi • Govoni, Aladino • Bautz, Ralf • Dahm, Torsten • (et. al.)
Abstract: The temporary Extended Pollino Seismic Experiment (FDSN network code Y4) monitored the earthquake swarm in the Pollino Range region, Italy, between September 2014 and April 2015. The experiment followed the Pollino Seismic Experiment, 2012-2014 (network code: 4A) [1] in the same area, further enhancing the detection and analysis capabilities there. It was part of a collaborative effort made by the German Research Centre for Geoscience (GFZ) and the Istituto Nazionale di Geofisica e Vulcanologia (INGV) within the CCMP-Pompei, FEFI and NERA projects. The Pollino Range region is located at the transition from the Southern Apennines chain to the Calabrian arc. Striking a volume of about 20x20x15 km, the swarm started in October 2010, culminated in a Mw=5.2 on 25 October 2012 and has continued since with a variable rate of activity. The area represents a seismic gap as there are no documented historical M>6 earthquakes during the last thousand years. The tectonic structures of the area are poorly known. The Y4 network consisted of 19 stations including 14 broadband and five short-period instruments. All instruments were provided by the Geophysical Instrument Pool Potsdam (GIPP) and the CCMP-Pompei project at GFZ and INGV. They were complemented by another four temporary IV stations installed by INGV. The short-period stations had Mark L-4C3D sensors with EDR digitizers. The broadband stations were equipped with STS2.5 seismometers and RefTek RT130S digitizers or Güralp CMG-ESP or Güralp CMG-40T seismometers and EDR digitizers. Eleven broadband (CSA0 to CSA10) were installed in a small-aperture detection array in the west of the range. The other 8 stations (broadband: CSB, CSE, CSD0 and short period: CSF, CSG, CSH, CSI, CSK) formed a network in the swarm area. The array and the network stations recorded in continuous mode at 200 Hz. The sensors were buried in the ground at 0.5 m depth except for CSB, CSE and CSD0 which were installed on the surface. High-precision station coordinates were obtained by using differential GPS measurements. The data have been used to analyze the earthquakes and seismogenetic structures and to discern the characteristics of the swarm sequence. Waveform data will be fully open after April 2017. [1] Pollino Seismic Experiment, 2012-2014, doi:10.14470/9N904956
# 2
Larose, Eric
Abstract: The experiments are performed down the Edward Bailey valley, in the Renland peninsula, Scoresby Sund, Greenland. General purpose: ambient seismic noise recordings are obtained to characterize the geometry/structure of the valley the geometry/structure of the glaciers the microseismicity of the glacier, the friction process, crack orientation and mechanisms the seismic activity of glacial rivers, the relation between hydrological flow and noise spectrum the localization and characterization of sub-glacial flow from surface recordings. Seismic stations were composed of 3C broadband Trillium compact seismometer, a Cube datalogger and a 12V (D-cell types, stacked) battery pack.The experiment splits into three surveys performed at three different sites, one after the other, from july to august 2016. In the first experiment, we deploy 11 stations, 9 of them on a flat sandy area covering, partly, immobile ice that seems to be blocked between the Bailey Glacier (upstream) and the Apusinikajik glacier (downstream). The 9 sensors are placed a few hundreds of meters from the Apusinikajik lateral front, the last 2 are placed on the glacier next to the collapsing front. In the second and third experiment (chronologically speaking), we deploy 10 and 8 stations, respectively. Each deployment is performed along a Bailey valley transect. The first one intercepts the front-end of the glacier and the sub-glacial river exit (flow of several m3/s). The second transect is performed some 850m upstream. Waveform data are available from the GEOFON data centre, under network code 3H, and are embargoed until summer of 2019.
# 3
Pilz, Marco • Parolai, Stefano
Abstract: A temporary local seismic network was installed in the basin of Norcia (Italy) in January 2009 and operated until May 2009. Several recordings collected by the network are earthquakes of the 2009, Mw 6.3 L'Aquila seismic sequence. The seismic equipments consisted of fifteen Earth-Data Loggers (24 bit) connected to Mark L4-3D sensors (1Hz). The stations continuously recorded at a rate of 100 samples per second, and the timing was provided by a GPS link. Waveform data are available from the GEOFON data centre.
# 4
GFZ German Research Centre for Geosciences • Institut des Sciences de l’Univers-Centre National de la Recherche CNRS-INSU
Abstract: The IPOC seismic network is part of the Integrated Plate boundary Observatory Chile (IPOC), a European-Chilean network of institutions and scientists organizing and operating a distributed system of instruments and projects dedicated to the study of earthquakes and deformation at the continental margin of Chile. In particular, the seismic network is jointly operated by the GFZ German Research Centre for Geosciences, Potsdam, Germany; the Institut de Physique du Globe Paris, France (IPGP); the Chilean National Seismological Centre (CSN); the Universidad de Chile, Santiago, Chile (UdC); and the Universidad Católica del Norte, Antofagasta, Chile (UCNA). The subduction plate boundary between the South American and the oceanic Nazca plates exhibits some of the largest earthquakes on Earth. The IPOC goal is to improve the understanding of both the physical mechanisms underlying these processes and the natural hazards induced by them. The observatory is designed to monitor the plate boundary system from the Peru-Chile border to south of the city of Antofagasta, from the coast to the high Andes, capturing both great and small earthquakes in this region. A key component of IPOC is its multi-parameter observatories, where at each site a suite of different physical parameters are measured continuously. So far about 20 such multi-parameter stations are installed. All of these sites are equipped with STS-2 broadband seismometers and accelerometers. Additional instrumentation at some of the stations includes continuous GPS, electric and magnetic field (MT), surface inclination, and climate (temperature, air pressure, humidity). Most sites transmit their data in near-real time using a suite of communication channels (VSAT, WiFi, telemetry etc.). Seismic instruments are deployed on concrete pedestals in bedrock caverns (a few meters deep) to measure ground shaking from earthquakes or other sources that last from a tiny fraction of a second to several hours. Strong-motion sensors are deployed next to the broadband sensors to increase the dynamic range and for earthquake engineering applications. Broadband data are freely distributed in real-time and archive data is also available. This DOI encompasses all IPOC seismic data; data is available under FDSN network code CX.
# 5
Asch, Günter • Heit, Benjamin • Yuan, Xiaohui
Abstract: A set of 60 seismological stations (45 short period and 15 broadband) was installed at 21°S between the coast in Chile (70°W) and the Eastern Cordillera in Bolivia (64°W) along a 600 km long profile and operated during two years in the Central Andes region. The stations operating at a rate of 50 samples per second (sps) recorded large and local events as well as quarry blasts from the copper mines in the vicinity of the profile. The results will be used to improve the crust velocity model and to identify the Andean shear zones and their extension to the west. In addition, a shorter profile consisting of 20 stations (10 short period and 10 broadband) was installed in Argentina along a 200 km profile at 26°S with the aim to investigate lithospheric delamination across the Cerro Galan caldera, one of the most prominent intra-plate volcanoes in the world. The instruments recorded local and teleseismic events during two years and were used to map the Moho and LAB, as well as to investigate the Galan Caldera by teleseismic tomography.
# 6
Heit, Benjamin • Yuan, Xiaohui • Mancilla, Flor de Lis
Abstract: We operated a densely spaced broadband seismic field experiment to study the structure of the crust and mantle lithosphere across the Sierra Nevada mountain range, southern Spain. The Sierra Nevada is one of the key areas within the complicated Betic-Alboran-Rif system. It contains the highest mountain of the Iberian Peninsula and is located in the close vicinity of a very deep seismic zone (>600 km depth). This region plays a decisive role in answering the question if subduction or delamination is the dominant geological process in the western Mediterranean. The seismic array, consisting of 40 broadband stations spaced 2 km apart (compared to earlier station spacing of ~50 km), has been deployed in September 2010 by a joint effort of GFZ Potsdam and University of Granada, and has been operated until the end of 2011. The proposed scientific work is the analysis of the data collected with the present experiment which includes mainly P and S receiver function analysis and surface wave tomography with ambient noise data. We will image the seismic structure and thickness variation of the crust and mantle lithosphere at high resolution and hence infer tectonic and geodynamic processes related to the Africa-Eurasia collision. The resulting structural details especially of the mantle lithosphere will contribute essentially to the recognition of the geodynamic deformations in the western part of the African-Eurasian plate collision. Data are available from the GFZ seismological data archive.
# 7
Yuan, Xiaohui • Mechie, James • Schurr, Bernd
Abstract: We study deep structures and geodynamic processes in the Tien Shan and Pamir collision zones, central Asia, with passive source seismic experiments in Kyrgyzstan and Tajikistan. In 2008, a total of 40 seismic stations were deployed predominantly along a 350 km long N-S profile and partly as a sparse 2D seismic network covering an area of 300x300 km of the central Pamir plateau. In 2009, the array was rearranged into a 2D network with higher station density. The proposed scientific tasks to study the crust and upper mantle with seismic methods include (i) teleseismic P and S receiver functions, (ii) shear wave splitting, (iii) location of local earthquakes and waveform inversion for source mechanism, (iv) seismic tomography using local and teleseismic earthquakes, and (v) tomography of surface waves and ambient noise.
# 8
Heit, Benjamin • Yuan, Xiaohui • Kind, Rainer • Asch, Günter
Abstract: The seismic array is part of a collaborative international passive-source seismic experiment in the southern Puna (25°S to 28°S) that aims to address fundamental questions on the processes that form, modify and destroy continental lithosphere and control lithospheric dynamics along Andean-type continental margins. The southern Puna is anomalous with respect to the rest of the Andean plateau in having a distinct magmatic and structural history, a large deficit in crustal shortening compared to its elevation and an underlying slab with a transitional dip between a steeper segment to the north and the Chilean flat-slab to the south. With the international project we proposed to test the hypothesis of the lithospheric delamination beneath the southern Puna. The total network consists of 75 seismic stations and has been operated in Argentina and chile for 2 years. The GFZ has contributed 30 stations with EarthData logger (EDL). Sensors include broadband Güralp 3ESP (60 s) and 3T (100 s) and short-period Mark L4 (1 s). Continuous data are freely available on the GEOFON. The US data can be requested from the IRIS.
# 9
Passarelli, Luigi • Roessler, Dirk • Aladino, Govoni • Maccaferri, Francesco • Moretti, Milena • (et. al.)
Abstract: The temporary Pollino Seismic Experiment, FDSN network code 4A, monitored the earthquake swarm in the Pollino Range region, Italy, between November 2012 and September 2014. The region is located at the transition from the Southern Apennines chain to the Calabrian arc. Striking a volume of about 20x20x15 km, the swarm started in October 2010, culminated in an Mw=5.2 event on 25 October 2012, and has continued since with a variable rate of activity. The area represents a seismic gap as there are no documented historical M>6 earthquakes during the last thousand years. The tectonic structures of the area are poorly known. The experiment was part of a collaborative effort made by the German Research Centre for Geosciences (GFZ) and the Istituto Nazionale di Geofisica e Vulcanologia (INGV) within the framework of the NERA and CCMP-Pompei projects. The 4A network consisted of 9 stations including 6 short-period and 3 broadband instruments, provided by GFZ. The permanent seismic network was complemented by the 9 GFZ stations and 5 IV stations temporarily installed by INGV. The short-period stations had Mark L-4C3D sensors with EDL digitizers. The broadband stations were equipped with STS2.5 seismometers and RefTek RT130S digitizers. Five short period and one broadband (CSA0 to CSA5) were installed in a small-aperture array in the west of the range. The other three stations (broadband: CSB, CSC and short period: CSD) were installed around the swarm area. The array and the network stations recorded in continuous mode at 200 Hz and at 100 Hz, respectively. The sensors were buried in the ground at 0.5 m depth except for CSB and CSD which were installed on the surface. High-precision station coordinates were obtained by using differential GPS measurements. The data have been used to analyze the earthquakes and seismogenetic structures and to discern the characteristics of the swarm sequence.
# 10
Roessler, Dirk • Hiemer, Stefan • Bach, Christoph • Delavaud, Elise • Krueger, Frank • (et. al.)
Abstract: Earthquake swarms occur frequently in Vogtland/West Bohemia at the German-Czech border. The link between these earthquakes and magmatic fluids that escape at the surface has been debated and investigated. The Rohrbach/Vogtland seismic array, installed by the University of Potsdam, Germany, was a small-aperture array that monitored the major earthquake swarm in 2008 and the background seismicity between October 16, 2008 and March 18, 2009. The array consisted of 11 stations equipped with MarsLite data loggers and Lennartz Le3D-5s seismometers. Data were recorded in continuous mode at 250 Hz. Sensors were buried in the ground at 0.5 m depth. High-precision station coordinates were obtained using differential GPS measurements. The array data has been used for analyses of earthquakes and seismic structures. Waveform data is fully open.
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